Are you trimming existing axles, or are you getting a cut-to-length like the ones Yukon makes?
If you're cutting an existing axle, take it to a shop. They'll be able to re-spline it after cutting pretty cheap. If you're using a cut-to-length, a wet saw would be preferable, but a chop saw will work. Don't do too fast of a cut to avoid the heat build-up, then bevel the end with a bench grinder and you're good to go.
We might have a different definition of cheap. Last time I had it done was a couple of years ago and it was $100 for a pair of axles to be shortened and re-splined. Poking around now it seems that 90-125 is the going rate. To me that's not bad for a job that's important that it gets done right and lacking the machinery and skill to do myself.